"A simple chest made from dried brinestalk"
Chests are immobile containers which contain loot. Artifacts, food, armor and more can usually be found. You can pick them up and move them elsewhere, they weigh 1+the full weight of anything inside of it. This makes it useful for making bases to store your loot.
Additionally, chests are involved in an exploit to greatly reduce the effects of confusion. By carrying only one chest and filling it with only Yuckwheat, the player can reliably select a piece of Yuckwheat (and eat it, curing your confusion) while confused, the chest will be the only item in your inventory with the open action available, and there will only be one item inside the chest, your Yuckwheat.